Here you can find the source of toNumber(char letter)
public static int toNumber(char letter)
//package com.java2s; /** This Source Code Form is subject to the terms of the Mozilla Public * License, v. 2.0. If a copy of the MPL was not distributed with this * file, You can obtain one at http://mozilla.org/MPL/2.0/. */// w ww. j a v a 2 s .c om public class Main { public static int toNumber(char letter) { switch (letter) { case ' ': return 0; case 'a': return 1; case 'b': return 2; case 'c': return 3; case 'd': return 4; case 'e': return 5; case 'f': return 6; case 'g': return 7; case 'h': return 8; case 'i': return 9; case 'j': return 10; case 'k': return 11; case 'l': return 12; case 'm': return 13; case 'n': return 14; case 'o': return 15; case 'p': return 16; case 'q': return 17; case 'r': return 18; case 's': return 19; case 't': return 20; case 'u': return 21; case 'v': return 22; case 'w': return 23; case 'x': return 24; case 'y': return 25; case 'z': return 26; // case 'A': return 27; case 'B': return 28; case 'C': return 29; case 'D': return 30; case 'E': return 31; case 'F': return 32; case 'G': return 33; case 'H': return 34; case 'I': return 35; case 'J': return 36; case 'K': return 37; case 'L': return 38; case 'M': return 39; case 'N': return 40; case 'O': return 41; case 'P': return 42; case 'Q': return 43; case 'R': return 44; case 'S': return 45; case 'T': return 46; case 'U': return 47; case 'V': return 48; case 'W': return 49; case 'X': return 50; case 'Y': return 51; case 'Z': return 52; // case '1': return 53; case '2': return 54; case '3': return 55; case '4': return 56; case '5': return 57; case '6': return 58; case '7': return 59; case '8': return 60; case '9': return 61; case '0': return 62; default: return 63; } } }